1. Field of the Invention
Embodiments of the invention relate to a photosensitive film, and more particularly, to an exposure method and exposure apparatus for a photosensitive film.
2. Discussion of the Related Art
Recently, various flat panel displays have been developed that solve the disadvantages of a cathode ray tube, such as heavy weight and large volume. Accordingly, the use of such flat panel displays is on the rise. These flat panel displays include a liquid crystal display, a field emission display, a plasma display panel, and an electro-luminescence display.
The thin films of these flat panel displays are formed by a plurality of mask processes. Each of the mask processes includes a thin film depositing (coating) process, a washing process, a photolithography process, an etching process, a photoresist removing process, and a testing/inspection process. More particularly, the photolithography process includes an applying process, in which a photosensitive film is applied onto a thin film formed on a substrate, an exposing process, in which the photosensitive film is exposed to light using a mask, and a developing process, in which the exposed photosensitive film is developed.
A related art exposure apparatus, which is used in the exposing process, exposes a photosensitive film using ultraviolet light generated from a mercury discharge lamp, for example. However, the discharge lamp of the related art exposure apparatus has a short life of only 1000 hours, which requires work stoppage whenever the discharge lamp is replaced, such that expenses are incurred due to both lamp replacement and lost production. Work stoppage is long because of a cooling period for the discharge lamp to dissipate the 1200° C. operating heat, actual replacement time, and recalibration time to properly position a replacement discharge lamp.
Light from the discharge lamp of the related art exposure apparatus include wavelengths of light unnecessary for exposure. Accordingly, the related art exposure apparatus requires an optical filter to filter out the unnecessary wavelength of light, and thus the related art exposure apparatus has a complex structure and large size. Further, the discharge lamp of the related art exposure apparatus must be maintain in an on-state to prevent the generation of cracks due to thermal stresses caused by frequently turning the lamp off and on. A shutter is additionally provided to block light emission when the discharge lamp of the related art exposure apparatus is not in use. Because the discharge lamp is maintained in the on-state, the related art exposure apparatus wastes electricity. Moreover, the discharge lamp of the related art exposure apparatus contains substances, such as mercury, that are harmful to the environment and thus additional disposal expenses are incurred in using the discharge lamp of the related art exposure apparatus.